| |
| VisualStudio instructions |
| |
| libpng version 1.6.34 - September 29, 2017 |
| |
| Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson |
| |
| This code is released under the libpng license. |
| For conditions of distribution and use, see the disclaimer |
| and license in png.h |
| |
| This directory contains support for building libpng under MicroSoft |
| VisualStudio 2010. It may also work under later versions of VisualStudio. |
| You should be familiar with VisualStudio before using this directory. |
| |
| Initial preparations |
| ==================== |
| You must enter some information in zlib.props before attempting to build |
| with this 'solution'. Please read and edit zlib.props first. You will |
| probably not be familiar with the contents of zlib.props - do not worry, |
| it is mostly harmless. |
| |
| This is all you need to do to build the 'release' and 'release library' |
| configurations. |
| |
| Debugging |
| ========= |
| The release configurations default to /Ox optimization. Full debugging |
| information is produced (in the .pdb), but if you encounter a problem the |
| optimization may make it difficult to debug. Simply rebuild with a lower |
| optimization level (e.g. /Od.) |
| |
| Linking your application |
| ======================== |
| Normally you should link against the 'release' configuration. This builds a |
| DLL for libpng with the default runtime options used by Visual Studio 2010. |
| In particular the runtime library is the "MultiThreaded DLL" version. |
| If you use Visual Studio defaults to build your application you will have no |
| problems. |
| |
| If you don't use the Visual Studio defaults your application must still be |
| built with the default runtime option (/MD). If, for some reason, it is not |
| then your application will crash inside libpng16.dll as soon as libpng |
| tries to read from a file handle you pass in. |
| |
| If you do not want to use the DLL, for example for a very small application, |
| the 'release library' configuration may be more appropriate. This is built |
| with a non-standard runtime library - the "MultiThreaded" version. When you |
| build your application it must be compiled with this option (/MT), otherwise |
| it will not build (if you are lucky) or crash (if you are not.) See the |
| WARNING file that is distributed along with this readme.txt. |
| |
| Stop reading here |
| ================= |
| You have enough information to build a working application. |
| |
| Debug versions have limited support |
| =================================== |
| This solution includes limited support for debug versions of libpng. You |
| do not need these unless your own solution itself uses debug builds (it is |
| far more effective to debug on the release builds, there is no point building |
| a special debug build unless you have heap corruption problems that you can't |
| track down.) |
| |
| The debug build of libpng is minimally supported. Support for debug builds of |
| zlib is also minimal. You really don't want to do this. |
| |
| WARNING |
| ======= |
| Libpng 1.6.x does not use the default run-time library when building static |
| library builds of libpng; instead of the shared DLL runtime it uses a static |
| runtime. If you need to change this make sure to change the setting on all the |
| relevant projects: |
| |
| libpng |
| zlib |
| all the test programs |
| |
| The runtime library settings for each build are as follows: |
| |
| Release Debug |
| DLL /MD /MDd |
| Library /MT /MTd |
| |
| NOTICE that libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used |
| the debug builds in your app and you changed your app to use /MD you will need |
| to change it back to /MDd for libpng 1.6.0 and later. |
| |
| The Visual Studio 2010 defaults for a Win32 DLL or Static Library project are |
| as follows: |
| |
| Release Debug |
| DLL /MD /MDd |
| Static Library /MD /MDd |
| |
| Also, be sure to build libpng, zlib, and your project all for the same |
| platform (e.g., 32-bit or 64-bit). |